What the heck is my tub coated with?

[Andy]

I have a small chip on the outside of my bathtub that the wife unit wanted fixed. OK, so I grabbed some white epoxy porcelain fix stuff. Before using, I figured I'd make sure the area was good and clean, and gave it a quick scrub with some denatured alcohol. Oh, oh

-- noticed I was actually removing the coating on the tub -- smearing the coating, and exposing something that looked like fiberglas (I'd always assumed that the tub was just a cheap-ass steel tub). This tub has never been "refinished". I can't imagine anyone using a lacquer or shellac on a tub (the only two coatings that I can remember that alcohol will strip that easily)...so what the heck is this stuff? Any ideas?

[jamesgangnc]

I thought they were all gelcoat like a boat. Doesn't come off with alcohol.

[Tegger]

Andy wrote in news:7a81adcf-574a-4e4a-a4e6- [e-mail]:

Does a magnet stick to the tub?

[krw]

Fiberglass tubs are, steel and cast iron are not. Sounds like a *really* cheap steel tub.

[Tegger]

" [e-mail]" wrote in news: [e-mail]:

Even the very cheapest steel tubs I've seen have ceramic (glass) coatings.

If the OP can dissolve his tub's coating with alcohol, I suspect the tub's just painted fiberglass, or maybe one of those plastic covers they apply when you're too cheap to replace a worn-out tub.

[aemeijers]

How can you not know what the tub is made of? Knuckle test, magnet test, bare-butt-on-a-cold-morning heat transfer test, any of those would quickly scream out what it is made of.

[Ed Pawlowski]

"aemeijers" wrote

You just gave me an idea for a new safety device. To prevent a drowning in the tub you insert a Magnetic Butt Plug to keep you from sliding under the water.

[krw]

TMI

[Andy]

Yup, magnet sticks. "tap test" sounds like a steel tub, too. Looks like the fiberglass-ish stuff is just on the rounded edges of the tub (something to help prevent chipping?).

[Andy]

[e-mail]:

Same here (steel tub =3D ceramic / porcelain coating in every case I've seen 'til now). Not this time, 'tho. And it isn't a cover -- the tub's been there since we had the place built (18 years ago). Other than the chip (which is on the outside corner of the tub, not on the bottom), it's been a good li'l tub.

[Andy]

I know what the tub is made of. What I don't know is what it is coated with. A steel tub with a coating that comes off with alcohol is, just, well, really weird.

[The Daring Dufas]

Would it have barbs to keep it in place?

TDD

[Bob F]

Is it really steel? Does a magnet stick to it? If so, It has probably been "refinished". But it must be a much better job than I've seen. Most are very obvious.

[Bob F]

Oops. I missed the "we had the place built" part. That makes the refinished idea unlikely.

[aemeijers]

innews: [e-mail]:

Mebbe the builder had an oopsie with the tub, and happened to have a real artistic painter on staff that fixed that spot with ordinary enamel. and it held up until recently?

Only other thought I have is that it was a REALLY cheap steel tub (like we installed in low-end houses and apartments back in the day), that were basically just stamped out and painted like car fenders.

[Andy]

[e-mail]:

ding-ding-ding -- we have a winner! I tested a couple of other areas of the bathtub, and the alcohol didn't touch it. Went back to the questionable area, and started hitting it hard with the alcohol (it was already fscked up from my original "cleaning", so nothing to lose), and stripped it back to a roughly 1/2" x 2" "ding" on the tub that had been filled with fiberglass and then painted. Damned nice job for a hack -- I hadn't noticed anything in 18 years of use. Suppose it must've been an automotive lacquer...don't know anything else alcohol would've stripped off so quickly.

Thanks for everyone's insights -- once I knew this wasn't something well known, it gave me the courage to experiment a bit more :-)